The present invention relates to a light radiating device for effectively diffusing light coming in through a light conducting cable or the like to the ambience.
To meet the increasing demand for energy saving, effective use of solar energy has been studied in various fields. For the most effective use of solar energy, it is the primary requisite that the solar energy be used as optical energy without being transformed into another kind of energy such as thermal energy or electrical energy. In light of this, the applicant has proposed in various forms a system in which solar radiation converged by lenses or the like is introduced into light conducting cables to propagate therethrough to desired locations and, then, diffused at the desired locations out of the cables. The system finds various applications as a light source such as for lighting rooms or causing photosynthesis for forced culture of plants.
Light advancing through a light conducting cable has directivity. Hence, concerning the application of the solar energy to lighting as stated above, the angular range available for the radiation of light is usually not larger than about 46 degrees when the light is discharged from a simply cut end of the light conducting cable. Such a narrow radiation range is incapable of lighting a room or the like in a desired manner. The applicant has made various propositions concerned with a light radiating device, or photoradiator, which effectively diffuses light propagating through a light conducting cable so as to radiate it over a desired range. The present invention is another successful implementation for such an attempt.